i tried to adjust T2 according to documentation, but i just don't see a change on the oscilloscope. cabling is correct now (fixed some wrong wires) and should be working IMHO.

T2 adjusts the noise clock offset. for setting up the noise clock CV you have to select external sweep. then follow the instructions. yo won't need an oscilloscope, just your ears (sound yes/no?).

if there is no change in noise sound at all, there is good news and bad news (as usual). the bad news: there must be something wrong. the good news is: both the circuit and the PCB is proven to be correct so you will get it working in the end.

Hey Unit-sound! Excellent looking MOTM panel! I am going to be working on a few of my FONIK modules over the weekend, and was wondering if you would be willing to post details on your panel design. Did you use Front Panel Designer for it? Looks sweet!

Hey Unit-sound! Excellent looking MOTM panel! I am going to be working on a few of my FONIK modules over the weekend, and was wondering if you would be willing to post details on your panel design. Did you use Front Panel Designer for it? Looks sweet!

The portion of the schematic involving the Noise Sweep is very perplexing to me. I have no doubt that this circuit works, but I'm having trouble understanding how it works.

Some time ago, I experimented with this IC. Although I didn't use a CV to sweep the noise clock, my circuit did have a pot which controlled the frequency of the internal noise clock, and this circuit was connected to pin 3 (and I think pin 4 also).

On Fonik's schematic, the Ext CV input, which is used to sweep the noise clock, is applied to pin 16 (Ext VCO Control). How can this pin be used to sweep the noise clock when it is for Ext VCO Control? Why not use pin 3? (Even the SN76477 datasheet recommends pin 3 for this purpose.)

Can somebody please explain how it is possible to sweep the noise clock using pin 16?

On Fonik's schematic, the Ext CV input, which is used to sweep the noise clock, is applied to pin 16 (Ext VCO Control). How can this pin be used to sweep the noise clock when it is for Ext VCO Control? Why not use pin 3? (Even the SN76477 datasheet recommends pin 3 for this purpose.)

Can somebody please explain how it is possible to sweep the noise clock using pin 16?

however, i have to say one word about quality. these boards are just a reorder of the 1st run from expressPCB. it is leadfree ROHS and i strongly recommend to store it not too long, or if you want to put it on the shelf for a longer time, store it in a small bag with silicon if possible, in order to keep it dry as possible.
i you one day find the pads have become dull just sand it carefully.

i'm just designing my panel at the moment
im wondering if you can confirm all the normalised connections in the panel
since im am using bananas i need to add a switch for each

so far i have noted

+5v > Gate in
noise out > s&h in

that's it.
and you do not have to normal the s&h in to the noise. you could patch it with your banana anyways.

Quote:

also your panel suggests to me that all of the pots are reversible attenuators/control. is this correct?

no. it is my old affliction: the +/- means nothing but more/less for me. not related to any actual measurements/voltages.

Quote:

i have also noticed you do not have the hold function on the lfo any more?
was there a reason for removing this?

i just don't need/want it.

Quote:

and lastly is the much difference between the gate and square output on the lfo?

yes, it is. the gate and trigger is uni-polar, above GND only. the triangel and square waves are centered around GND.
furthermore the phase of the gate is shifted by 180 degrees in relation to the square. i don't know why thomas designed it this way. any ideas anybody?

concerning the LEDs: you show one LED for the tri/square and one for the gate/trigger outputs. it is actually a good idea to have a separate LED for the gate out at least (see above: phase, now that we talked about it i will perhaps add it to my module in future). the PCB/design does not provide this, though. there is one LED for the tri/square out and one for the current LFO status (on/off)._________________
cheers,
matthias
____________
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